Hugh Everett is the father of the Many Worlds Interpretation of quantum mechanics, the first physicist to propose that we exist in a potentially infinite series of parallel dimensions. He's also the father of Eels frontman Mark Oliver Everett, who was just 18 when his father died. Tonight, PBS airs “Parallel Worlds, Parallel Lives,” Mark Everett's documentary on his father's life and work.Everett has previously explored his family tragedies in the Eels album Electro-Shock Blues. But here he traces the path of his late father's research, meeting with Hugh Everett's friends and colleagues to gain a deeper understanding of Everett's work and why it was so significant. He also learns why his father eventually left theoretical physics for defense work, and how devastating the elder Everett found Niels Bohr's rejection of his ideas.